Direct-acting engine.



No. 637,8I0. Patented Nov. 28, |899.

E. C. MEISSNER.

DIRECT ACTING ENGINE.

(Applicaeion mea my 4. 1599'.;

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@HHH N No. 637,3m. Patemd Nov. 28, |899.

` E. C. MEISSNER.

. DIRECT ACTING ENGINE.

`(Application led May 4, 1899.) (No Model.) 2 Sheets-Shea) 2.

A@ m um UNITED STATES PATENT Omen.

EDVARD CHARLES MEISSNER, OF ST. LOUIS, MISSOURI.

DIRECT-ACTING ENGINE.

SPECIFICATION forming part of Letters Patent No. 637,810` dated November 28, 1899.

Application iiled May 4, 1899. Serial No. 715,540. (No model.)

To LZZ whom, it may concern: 1

Be it known that LEDWARD CHARLES MEIss- NER, a citizen of the United States, residing at the city of St. Louis, State of Missouri, have lnvented a certain new and useful Improvement in Direct-Acting Engines,of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which-L Figure l is a longitudinal sectional view through my improved direct-acting engine, showing the piston in its rearmost position. Fig. 2 is a similar view, the handle being omitted, showing the piston in its forward position. Fig. 3 is a similar view showing the piston in its extreme forward position. Fig. 4 is a view showing the rear face of the valveblock. Fig. 5 is alongitudinal sectional View l through said valve-block. Fig. 6 is a view der on line 15 15, Fig. 13.

showing the front face of the valve-block.'

Fig. 7 is a cross-sectional view on line 7 7, Fig. 5. Fig. 8 is a cross-sectional view on line 8 8, Fig. 5. Fig. 9 is a longitudinal sectional view through line 9 9 of Fig. 8. Fig. 10 is an edge View of a sleeve which is introduced into the rear end of the valve-block. Fig. 1l is a cross-sectional view through said sleeve. Fig. 12 is arear end elevational View of the barrel or cylinder. Fig. 18 is a longitudinal sectional view of said barrel or cylinder. Fig. 14 isa cross-sectional view through said cylinder on line 14 14, Fig. 13. Fig. 15 is a cross-sectional View through said cylin- Fig. 16 is lan elevational View showing the handle and a portion of the cylinder, the flange of the handle being broken away to more clearly show the manner of locking the coupling sleeve in position. Fig. 17 is a rear edge elevational view of the coupling-sleeve clamping the cylinder and handle together; and Fig. 18 is a longitudinal sectional view through said coupling-sleeve.

This invention relates to a new and useful improvement in direct-acting engines of that class commonly known as pneumatic hammers, in which a chisel or tool is loosely introduced into the nose of the cylinder for receiving impacting blows from the piston.

The engine is designed to be heldin the hand ofan operator and guided in its work. Fluidpressure, usually in the form of compressed air, is supplied to the engine through the medium of flexible hose or supply-pipe, which is connected to the outer end of the handle. A throttle-valve under control of the operator controls and regulates the admission of pres= sure uid to the engine.

The object of this present invention is to construct an engine of the character described which is simple, cheap, and effective in operation and one which is free from vibrations usually present in engines of this class, which vibrations render the handling of the tool by the operator extremely tiresome and difficult.

In an application led by me on or about December 13, 1898, Serial No. 699,117, I have lshown and described an engine such, as is illustrated in the accompanying drawings, and this present application may be said to relate particularly to the construction of the controlling-valve for admitting and exhausting pressure to and from the spaces at the rear end of the piston and its controlled ports. For a better understanding of the engine shown and described in my former applicationIwill now describe the construction of the same and the manner in which my improved valve co operates therewith.

In the drawings, a indicates a handle provided with a suitable inlet duct 0r port, through which the pressure is supplied to the engine. This port terminates at the out-er end of the handle, and a threaded opening b is provided for the attachment of the hose or suitable nipple.

c indicates a thimble threaded into the base of the handle and across a live -pressure chamber d, said thimble receiving a sliding throttle-valve e, which is held in a closed p0- sition by a spring f. A rod g, slidingly mounted in the handle, bears against the valve c at one end, and a lever h, pivoted at t', bears against the other end of rod g. The spring f, which tends to hold the throttlevalve home, bears at its other end against a nut j, which is interiorly threaded in the thimble c. Nut j is provided with an outwardly-extending stem 7c, angular in crosssection, which is received in a correspondingly-shaped opening in a cap-piece Z, which f, is held inits outer. position by a spring fm, in-

terposed therebetween and the nut j. A pin n, introduced into the outer end of thimble c after the parts are assembled, bears against the outer face of the flange on the inner end of the cap-piece. and fits in suitable notches o, provided in 'the outer face of said flange, whereby when said cap-piece is pressed inwardly it slides on stem k andbeing disengaged from thepin fn is capable of being turned to adjust the-nut j inwardly or outwardly, which adjustment regulates the amount of travel, and consequently the availablearea, of the throttle-valve. sure is released from the cap-piece, the spring fm, forces the same outwardly and causes an engagement between one of the notches thereof and the pin n, which prevents accidental rotation of the parts.

A by-pass 19 is provided within the thimble c to conduct pressure behind the throttlevalvev for the purposeof balancing said valve when in an open position, so that the same may be easily operated-byits spring, and also for assisting in holding said valve in a closed position. y

The supply-duct d is located to onev side Y of the slot q, in which thelever his mounted,

v and opens into a concentric groove fr in the s leeve 1n its .home position and prevent accidental unscrewing thereof, which would Ase-` handle-base. The handle-base is provided with an interiorly-threaded fiange s, which engages a collar or coupling-sleeve t, whose forward end is provided withan inturned flange u, fitting under a ring or'flange fu, formed at the rear end of the cylinder. The valve-block or-that part of the engine which receives the piston-controlling valve is clamped between the handle-base and the end of the cylinder by means of this coupling-sleeve, and in lorder to lock the couplingriously affect the Operation of the engine, I notch orform a seriesof serrations w ony the rear edge of 'this coupling sleeve, yas shown more clearly in Figs. 16, 17, and 18,

and mount in the dange s of the handle a spring-pressed pawl or dog ,which is permitted to ride over said serrations when the collar is being screwed home and which pre- Y vents the accidental unscrewing of said col-` lar. This dog wis mounted onastem,around which is wound a torsional spring y, one end of'said torsional spring enteringthelange and the other end the stem or a cap-piecel z, arranged on the outer end of the stem and by'which the same'` can be turned to raise the. dog out of engagement wit-h the serrations on the end of the k(':oupling-sleeve whenever it is desired to unscrew theI said sleeve.. The operation of this dog is shown more clearly in Figs. 1 andl. A I will now describethe port arrangements and the manner in which pressure is admitted to the piston and its controlling-valve.

AThe cylinder or barrel,which I have marked 420 asan entirety, is bored to two Vdifferent diameters, the larger of which receives the head 2l of the piston and the smaller the `body portion-22 of said piston, said body portion having a reduced annulus 23. When the chisel-shank is in position, the piston moves forward and delivers an impacting blow, being arrested at such forward movement at practically the point indicated in Fizg. 2. Ports 24, 25, and 26' open into the forward end of the larger bore ofthe cylinder near the shoulder or the beginning of the smaller bore, these portsv registering` with corresponding ports 27, 28, and 29, formed in the valve-block' and which open at their rear ends into the live-pressure chamber or concentric groove fr. Pressure is thus conducted under or in advance of the larger head of the piston and tends at all times to f'o-rce said piston rearwardly. In othery words,

there is a constant pressure in advance of the piston and an intermittent pressure behind the larger head of the piston. This intermittent pressure-is controlled by a valve the' valve-block, said valve being of two different diameters, the larger, which I have 'marked 31, being on the forward end of the valve, whilev the smaller, 32, forms the rear end of the valve. These two portions of the valve are divided by an enlarged head or flange 33, which operates in vwhat may be called the largest b ore 43 of the valveblock. This valve-block, as shown more clearly in Figs. 5 and 9, is bored to three different diameters, t-he largest of which receives a sleeve 35, (in the rear end'of the valve-block,) and the bore of this sleeve forms va chamber in which the smallest diameter 32 of the val ve operates. The central head of the' valve operates in the bore 34 of the valve-block, as above described, while the larger body portion of the valve operates inthe smallest bore 36 of the valve-block. Sleeve 35 has a seatrformed in its rear end,

-in which is received a solid plate 37, while the valve-block and sleeve areformed with radial openings registering with each other,

Vwhich I have 'marked 38, said openings leading to an exhaust space or chamber 39,formed between the ange of the handle-base and valve'- block, said chamber communicating with the atmosphere through openings 40. Valve 30: is formed withan axial opening 4l extending entirely through the same, which opening when the valve is. moved forwardly serves to exhaust pressure from the rear end of the cylinder,said pressure escaping through the openings 38, which are unclosed when the valve is in such forward position. When the valve is thus forward, the body portion 3l projects a little distance into the cylinder and is designed to cooperate with a stem 42 on the piston, to be hereinafter described. Each of the ports 27, 28, and 29 open into the bore 36 of the `valve-block through ports 43, which ports 43 are opened and closed by the larger body portion 31 of the valve in its re- IOO IIO

90 '30, preferably centrally arranged relative to ciprocation. Leading from the rear end of the bore 34 of the valve-block is a duct or passage 44, which opens into the smaller bore of the cylinder near its rear end, said passage being opened or closed by the forward end of -the piston by its reduced annulus 23, which annulus in one position of the piston admits pressure into the bore 34 and in another position of the piston establishes communication between the duct 44 and the exhaustopening 45 in the cylinder, located slightly in advance of the port 44. In order to accommodate the displacement of air in the bore 34 in front lof the head of the valve, I provide a port 46 and which opens into the exhaust-chamber 39 through a groove 47, as shown more clearly in Figs. 8 and 9. This port 46 serves no purpose except to relieve the valve of pressure in front of its head when the same moves forwardly and to admit air at atmospheric pressure when the valve moves rearwardly.

The operation of the engine as above described Vis as follows: Assuming the parts to be in position as shown in Fig. l and pressure admitted to chamber d, when lever h is moved forwardly it will unseat the throttlevalve to admit pressure to the annular chamber r, from which chamber pressure is conducted through to ports 27, 28, and 29 in reglstration with the ports 24, 25, and 26 and admitted into the larger bore of the cylinder near the forward end thereof. Under such conditions the tendency of the piston is to move rearwardly, and in so doing the stem 42 contacts with the forward end of valve 30 and forces said valve rearwardly, so as to close the exhaust-ports 38 and open the inlet-ports 43 to admit pressure behind the piston. The piston now moves forward, as the area of the rear end of the piston exceeds the area of the shoulder, being the difference between the larger and smaller bores of the cylinder, said forward movement continuing until the reduced annulus 23 opens the port 44 to pressure, which port admits said pressure behind the head of the valve, causing said valve to move forward, as shown in Fig. 2. The forward end of the piston now delivers an impacting blow on the shank of the chisel introduced into the end of the cylinder, after which the pressure behind the piston exhausting through the axial bore 41 of the valve, the exhaust-passages 38, the exhaust-chamber 39, and into the atmosphere through the openings 40 will permit the pressure in front of the larger head of the piston to move said piston rearwardly until its stem 42 contacts with the forward end of valve 30 and moves said valve rearwardly to close the exhaustpassages 38 and open the inlet-passages 43, as above described.

It is desirablein this class of engines to provide means whereby the piston will cease operating in the absence 0f the tool-shank without necessitating the operator closing the throttle-valve every time he changes the position of the tool with respect to the work being done, and to accomplish this I permit the piston to move forwardly to an abnormal position in the absence of the tool-shank, so as toopen the ports 50, 5l, and 52, being at the extreme forward ends of ducts 24, 25, and 26, and which in normal operation were in front of the larger head 21 of the piston, and also open ports 53, 54, and 55, leading from ports 24, 25, and 26, respectively, just to the rear of ports 50, 51, and 52. No pressure now being in front of the piston under these conditions the pressure behind the piston will hold it in such forward position until the toolshank is again inserted to move the piston rearwardly to the position shown in Fig. 2 0r ings 53, 54, and 55; but by reason of the pos-` sibility of accidental displacement of valve 30 from such rearward position. which might result in shutting off this pressure behind the piston and opening the exhaust of such pressure, I prefer to make the cessation of movement of the piston positive by providing the ports 53, 54, and 55. It will be seen that the exhaust behind the head of the valve is open to the exterior through the port 44 and, further,that accidental displacement of the valve in the presence of the ports 53, 54, and 55 is prevented by reason of the constant pressure against the forward end of the valve. In the front end of the cylinder I prefer to introduce a hard-metal bushing or sleeve 56 to receive the tool-shank. The forward e nd of the piston is also, preferably, provided with a groove 57, having notches 58, opening in front thereof, for the purpose of giving a lead to the valve-exhaust in advance of the rearmost position of the piston. Openings 59 are provided in the forward end of the cylinder back of the bushing 56 to admit the-intake and outward passage of the air drawn in and forced out by the cylinder in its reciprocations.

It will be noticed that I h ave referred to several of the ports as being in triplicate for the purpose of admitting and exhausting a large volume of pressure fluid; but it is obvious that but one or more of such ports can be used, if desired.

By having the body portions 31 and 32 of the valve of different diameters, the forward being the greater, said valve is thereby unbalanced, with a tendencyat all times to force said valveto the rear, which tends to relieve the valve of any injurious shocks or jars resulting from contact of the piston-stem 42 therewith. This increased area at the forl'OO ' described without in the least departing from ware ena of the valve likewise holds said valvein itsy rearm ost position when the piston Vis in its abnormal forward position, as shown in Fig. .3. This unequal area of the valve likewise prevents the valve from throbbing the nature and principle of my invention.

Having thus described myinvention, what I claim, and desire to secure by Letters Patent, isv 1. The combination with the handle-base and rotary coupling-sleeve, which latter is formed with a series of serrations or notches upon its rear end, of a spring-pressed dog Vmounted'in said handle-base for engaging said notches and preventing said couplingsleeve from unscrewing, and a jam-nut L mounted on said collar or coupling-sleeve,

and engagingthe handle-base; substantially as described.

2. The combination with a handle-base formed with a flange s, of a valve-block abutting against said handle-base, a cylinder 20,

'- provided with a flange fu, at its rear end and abutting against said valve-block, acollaror coupling-sleeve t, formed with an inturned flange u, at its front end, which cooperates with the cylinder-flange v, said couplingsleeve havinga threaded connection with the iiange s, a jam-nut threaded in the forward end of the coupling and impinging against the forward end of ange s, and a dog 00,. engaging notches or serrations w, at the rear of said coupling-sleeve, and saidv dog being mounted in the flange of the handle-base, and being provided with a spring for causing its engagement with the collar or couplingsleeve; substantially as described.

3. The combination, with a threaded flange s, of a coupling-sleeve t carrying a jam-nut,

- both of which engage said iange, said coup- `ling-sleeve being provided with notches or serrations on its engaging end, a dog pivotally mounted in the flanges, a torsional spring for holding said dog in engagement with the coupling-sleeve, and a cap-piece xed on -the dogs spindle, by which the dog may-be disengaged from the .coupling-sleeve; substantially as described.

4.. `The combination with a cylinder bored to two diderent diameters, of a piston of corresponding diameters arranged in said cylin.- der, and a piston-controlling valve of two diameters, the larger of which projects into the larger bore of the cylinder, whereby said valve is positively thrown in one direction by said piston, and a port for intermittently admitting pressure at the other end of-sa'id valve substantially as described. v

l5. The combination with a cylinder bored to two different diameters, of -a piston of corresponding diameters arranged therein,` said cylinder being provided with yports for admitting constant pressure in front ofthe larger head of said piston, and a valve of two dierent diameters, the larger of which controls a port for intermittently admitting pressure behind the larger head of said piston, a central head on said valve, and aport which is controlled by said piston, for intermittently admitting and exhausting pressure behind the head of said valve; substantially as described.

6. The combination with a cylinder formed with two diii'erent diameters, of a .piston arranged in said cylinder, the body portion of said piston operating in the smaller diameter, and the larger head of said piston in the larger diameter, said head being connected to said body portion by a reduced shank, of a valveblock arranged at the rear end of said cylinder, saidV valve-block containing a valve of two diameters, and a central head, which op-` erate in correspondingly-bored openings, a pressure-supply passage having a port which constantly opens in advance of the larger head of the piston, and having a port which is controlled by said valve, which port intermittently admits pressure behind the larger head of the piston, and a port-opening behind the head of the valve, which port is controlled by the piston; substantially as described.

7 The combination with a valve block formed with an inlet-passage 27, port 42, exhaust-space 39, and port 44:, of a hollow valve 80, provided with a head, and with an axial bore 4l, which cooperates with the exhaustpassage when the valve is in-a forward position, and a piston for positively moving said valve to the rear for .closing said exhaustpassages and opening the inlet-port 42; substantially as described.

8. The combination with a cylinder formed with a bore of two diameters, of a piston of corresponding diameters arranged insaid bore, a valve-block abutting against the rear end of the cylinder, a valve 80, slidingly -m'ounted' in said valve-block, said valve having an opening throughout its length, the f orlward'end of which valveprojects into the cylinder-bore, a head on said valve, and suitable port `arrangements whereby .pressure is con- -stantly admitted to force the piston to the rear, the pressure behind said `piston being exhausted through the hollow valve, the piston near the rear extremity of its stroke conv tacting with the valve to move. the same rearwardly and` open a live pressure-port'to admit a preponderance of pressure behind the piston; substantially as described.

9. In a pneumatic hammer, the combination with a cylinder bored to two di'ferent diameters, with a shoulder between, a pressure-supply duct` opening into the larger vchamber near its forward end, a piston hav- IOO IIO

ing an enlarged head fitting in the larger bore, and a small body portion fitting in the small bore, said body portion having a reduced annulus, a valve comprising a small body portion at its rear end, a central head, and a larger body at its forward end which projects into the cylinder, and which isstruck by the piston to be moved in one direction, and a port for intermittently admitting pressure behind the central head of said valve for throwing the same; substantially as described.

l0. The combination with a cylinder formed with bores of two different diameters, of a piston arranged therein, a valve for controlling the admission of pressure to, and its exhaust from, the chamber behind the piston, said valve comprising a small body portion at its rear end, a central head, and a larger body at its forward end projecting into said chamber in one of its positions where it is struck by the piston and moved in one direction, a passage leading from behind the valve and opening into the piston-chamber by a port located in advance of the shoulder between the bores of the cylinder, which port is adapted to be opened and closed by the piston, an exhaust-port 45, in the cylinder in advance of said last-named passage, said cylinder being likewise provided with a portopening 53, for admitting pressure behind the piston when said piston has moved forward beyond its normal operating position; substantially as described.

ll. The combination with a cylinder bored to two different diameters, of a piston operating in said cylinder, said piston having constant pressure in front of its larger diameter for forcing the sam'e rearwardly, and a valve for intermittently admitting and exhausting a preponderance of pressure behind the larger diameter of the piston, said valve comprising a body portion of two diameters and a central head, said valve being also formed with an opening throughout its length, and a port, which is controlled by said Apiston for admitting and exhausting pressure to and from behind said valve-head; sub stantially as described.

In testimony whereof I hereunto aiiix my signature, in the presence of two witnesses, this 29th day of April, 1899.

EDWARD CHARLES MEISSNER. Witnesses:

F. R. CORNWALL, ANNA S. GRAY. 

